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** This file is part of the examples of the Qt Toolkit.
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#include "threadrenderer.h"

QList<QThread *> ThreadRenderer::threads;


RenderThread::RenderThread(const QSize &size)
    : surface(0)
    , context(0)
    , m_renderFbo(0)
    , m_displayFbo(0)
    , m_renderNst(0)
    , m_size(size)
{
    ThreadRenderer::threads << this;
}


void RenderThread::renderNext()
{
    context->makeCurrent(surface);

    if (!m_renderFbo) {
        // Initialize the buffers and renderer
        QOpenGLFramebufferObjectFormat format;
        format.setAttachment(QOpenGLFramebufferObject::CombinedDepthStencil);
        m_renderFbo = new QOpenGLFramebufferObject(m_size, format);
        m_displayFbo = new QOpenGLFramebufferObject(m_size, format);
        m_renderNst = new RenderNst();
        //m_renderNst->openglInitStructures(context->functions());
        m_renderNst->openglInitStructures(NULL);
    }

    m_renderFbo->bind();
    //context->functions()->glViewport(0, 0, m_size.width(), m_size.height());
    glViewport(0, 0, m_size.width(), m_size.height());
    m_renderNst->updateEmulator();
    //m_renderNst->opengl_blit(context->functions());
    m_renderNst->opengl_blit(NULL);


    // We need to flush the contents to the FBO before posting
    // the texture to the other thread, otherwise, we might
    // get unexpected results.
    //context->functions()->glFlush();
    glFlush();
    m_renderFbo->bindDefault();
    qSwap(m_renderFbo, m_displayFbo);
    context->doneCurrent();

    emit textureReady(m_displayFbo->texture(), m_size);
}

void RenderThread::shutDown()
{
    context->makeCurrent(surface);
    m_renderNst->opengl_cleanup();
    delete m_renderFbo;
    delete m_displayFbo;
    delete m_renderNst;
    context->doneCurrent();
    delete context;

    // schedule this to be deleted only after we're done cleaning up
    surface->deleteLater();

    // Stop event processing, move the thread to GUI and make sure it is deleted.
    exit();
    moveToThread(QGuiApplication::instance()->thread());
}

void RenderThread::eventKeyPress(int i)
{
    m_renderNst->cNstPads->pad[0].buttons |= i;
    //renderNext();
}

void RenderThread::eventKeyUp(int i)
{
    m_renderNst->cNstPads->pad[0].buttons &= ~i;
}



TextureNode::TextureNode(QQuickWindow *window)
    : m_id(0)
    , m_size(0, 0)
    , m_texture(0)
    , m_window(window)
{
    // Our texture node must have a texture, so use the default 0 texture.
    m_texture = m_window->createTextureFromId(0, QSize(1, 1));
    setTexture(m_texture);
    setFiltering(QSGTexture::Linear);
}

TextureNode::~TextureNode()
{
    delete m_texture;
}

// This function gets called on the FBO rendering thread and will store the
// texture id and size and schedule an update on the window.
void TextureNode::newTexture(int id, const QSize &size) {
    m_mutex.lock();
    m_id = id;
    m_size = size;
    m_mutex.unlock();

    // We cannot call QQuickWindow::update directly here, as this is only allowed
    // from the rendering thread or GUI thread.
    emit pendingNewTexture();
}


// Before the scene graph starts to render, we update to the pending texture
void TextureNode::prepareNode()
{
    m_mutex.lock();
    int newId = m_id;
    QSize size = m_size;
    m_id = 0;
    m_mutex.unlock();
    if (newId) {
        delete m_texture;
        m_texture = m_window->createTextureFromId(newId, size);
        setTexture(m_texture);

        markDirty(DirtyMaterial);

        // This will notify the rendering thread that the texture is now being rendered
        // and it can start rendering to the other one.
        emit textureInUse();
    }
}




ThreadRenderer::ThreadRenderer()
    : m_renderThread(0)
{
    setFlag(ItemHasContents, true);
    m_renderThread = new RenderThread(QSize(512, 512));
}

void ThreadRenderer::ready()
{
    m_renderThread->surface = new QOffscreenSurface();
    m_renderThread->surface->setFormat(m_renderThread->context->format());
    m_renderThread->surface->create();

    m_renderThread->moveToThread(m_renderThread);

    connect(window(), SIGNAL(sceneGraphInvalidated()), m_renderThread, SLOT(shutDown()), Qt::QueuedConnection);

    m_renderThread->start();
    update();
}



QSGNode *ThreadRenderer::updatePaintNode(QSGNode *oldNode, UpdatePaintNodeData *)
{
    TextureNode *node = static_cast<TextureNode *>(oldNode);

    if (!m_renderThread->context) {
        QOpenGLContext *current = window()->openglContext();
        // Some GL implementations requres that the currently bound context is
        // made non-current before we set up sharing, so we doneCurrent here
        // and makeCurrent down below while setting up our own context.
        current->doneCurrent();

        m_renderThread->context = new QOpenGLContext();
        m_renderThread->context->setFormat(current->format());
        m_renderThread->context->setShareContext(current);
        m_renderThread->context->create();
        m_renderThread->context->moveToThread(m_renderThread);

        current->makeCurrent(window());

        //in c++ thread run ready
        QMetaObject::invokeMethod(this, "ready");
        return 0;
    }

    if (!node) {
        node = new TextureNode(window());

        /* Set up connections to get the production of FBO textures in sync with vsync on the
         * rendering thread.
         *
         * When a new texture is ready on the rendering thread, we use a direct connection to
         * the texture node to let it know a new texture can be used. The node will then
         * emit pendingNewTexture which we bind to QQuickWindow::update to schedule a redraw.
         *
         * When the scene graph starts rendering the next frame, the prepareNode() function
         * is used to update the node with the new texture. Once it completes, it emits
         * textureInUse() which we connect to the FBO rendering thread's renderNext() to have
         * it start producing content into its current "back buffer".
         *
         * This FBO rendering pipeline is throttled by vsync on the scene graph rendering thread.
         */
        connect(m_renderThread, SIGNAL(textureReady(int,QSize)), node, SLOT(newTexture(int,QSize)), Qt::DirectConnection);
        connect(node, SIGNAL(pendingNewTexture()), window(), SLOT(update()), Qt::QueuedConnection);
        connect(window(), SIGNAL(beforeRendering()), node, SLOT(prepareNode()), Qt::DirectConnection);
        connect(node, SIGNAL(textureInUse()), m_renderThread, SLOT(renderNext()), Qt::QueuedConnection);

        connect(this, SIGNAL(signalKeyPress(int)), m_renderThread, SLOT(eventKeyPress(int)), Qt::QueuedConnection);
        connect(this, SIGNAL(signalKeyUp(int)), m_renderThread, SLOT(eventKeyUp(int)), Qt::QueuedConnection);

        // Get the production of FBO textures started..
        QMetaObject::invokeMethod(m_renderThread, "renderNext", Qt::QueuedConnection);
    }

    node->setRect(boundingRect());

    return node;
}

#include "threadrenderer.moc"
